Bachelor of Science in Civil and Environmental Engineering

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Assessing the use of Polyethylene Terephthalate fibre in reinforcement of lime-stabilised expansive soils
(Uganda Christian University, 2024-05-02) Mark Manana
Expansive soils are soils associated with constant volumetric change due to alternations in the moisture present in such soils, and such volume variations can lead to the expansive soils being unsuitable for use as subgrade material. The research was focused on the use of Polyethylene Terephthalate fibre in the reinforcement of hydrated limestabilised expansive soils to improve the properties of these soils. The research had specific objectives which were achieved by following a methodology that had implemented laboratory tests such as Sieve analysis, Atterberg Limits, California Bearing Ratio, Unconfined Compressive Strength, Free Swell Index, and Proctor Compaction on the neat soil along with other samples with a constant 6% content of Lime and varying percentages of fibre from 0 % to 2 %. There was a Tensile strength test done on the fibre. The tests were done following a given set of standards, after which the results on the neat sample found the soil to be expansive clayey soils and the fibrereinforced soil that was lime stabilised had the optimum mix ratio of 6% lime and 1.5 % fibre. The optimum mix ratio had a California Bearing Ratio of 54 % and an Unconfined Compressive Strength of 0.59 MPa. The results of the soil mixed with 1.5 % fibre and 6 % lime all matched the standards of subgrade material according to the Ministry of Works and Transport, General Specifications for Road and Bridge Works, 2005 manual. This implied that hydrated lime and Polyethylene Terephthalate fibre can be implemented in the improvement of properties of expansive soils to acceptable standards for subgrade material. There is a need for more research into the use of other fibres in the reinforcement of lime-stabilised soils.
Investigating the use of Water Lettuce for the Treatment of Wastewater at Kakoba Treatment Plant
(Uganda Christian University, 2024-04-22) Precious Mirembe
This research focuses on supplementing the wastewater treatment processes at Kakoba Waste Stabilization ponds using phytoremediation (using aquatic plants). There has been a positive response in harnessing the technology of plants to clean wastewater. Improperly treated domestic wastewater is quite harmful to the environment. Scientists are intricately studying this approach and the realization is its cost effectiveness, ecofriendly attributes and ability for it to run with no need for energy. The major aim of this specific study is to investigate how effectively Water Lettuce remove nutrients, and BOD from secondary treated wastewater. It put a test the polishing abilities of domestic wastewater. Treatment was executed in two troughs, one tub without the water lettuce was taken as the control unit and the second labeled the treatment unit that had the water lettuce. The troughs were of dimensions 0.7m×0.5m×0.3m. The sewage samples were assessed for three pollutants, T.N and T.P. After 10 days, the results were impressive from the treatment, they showed that water lettuce removed 80.93% and 77.90% removal efficiency of T.P and T.N respectively. BOD5 analysis was also carried out for 15 days and the results portrayed a percentage reduction of 86.16% on the 15th day. Because the effluent from the treatment unit met the discharge standards for T.N, T.P and 〖BOD〗_5 it was safe to be released into the environment. This study focused on optimizing the existing infrastructure in a to meet the present demands in a cost effective and environmentally sustainable manner.
Assessing the Use of Alkali-Activated Steel Slag in the Removal of Heavy Metal Ions From Wastewater
(2024-04-17) Phinehas Okiror
The release of wastewater containing heavy metals into the environment poses a huge threat to human health and the aquatic environment at large. In order to remove heavy metals from wastewater, adsorption methods are commonly utilized. This study investigated the effectiveness of alkali-activated steel slag in the removal of removal of heavy metals from wastewater. The research involved the characterization of wastewater samples to identify target heavy metals and their initial concentrations, steel slag characterization, alkali activation of the steel slag and the determination of the maximum adsorption capacity through batch adsorption experiments. The mean heavy metal concentrations determined were 0.43 𝑚𝑔/𝑙 for Lead (Pb) and 0.01 𝑚𝑔/𝑙 for Copper (Cu). XRF analysis of the steel slag showed it was made up of several oxides with Silicon Dioxide having the largest percentage. The maximum adsorption capacity determined was 78.99𝑚𝑔/𝑔. Based on the determined adsorption capacity, breakthrough curve data, and desired flow rate, a fixed-bed adsorption tank was designed to optimize the removal of heavy metals from wastewater streams on a larger scale. This research demonstrated the potential of activated steel slag as a cost-effective and eco-friendly approach for heavy metal removal from wastewater.
Assessing the Use of Activated Carbon to Increase Biogas Production
(2024-04-15) Faith Wanadi Angeango
The enhancement of biogas production, specifically methane enrichment is critical for improving the efficiency and viability of biogas as a renewable energy source. This report examines the role of activated carbon in increasing methane yield and the quantity of biogas produced in a digester at NALIRRI by the Direct interspecies electron transfer Process (DIET). Activated carbon known for its high surface area, electrical conductivity and porosity provides a conducive environment for the adsorption of inhibitory compounds and the DIET process. Furthermore, it facilitates a more stable and enhanced microbial activity leading to increased biodegradation and methane production. Experimental setups incorporating various concentrations of activated carbon were monitored and analyzed. Parameters like pH, temperature and organic loading rate were monitored alongside the addition of activated carbon to maximize methane output. The results indicate a significant increase in methane production with the addition of activated carbon and it can contribute to the development of a cost-effective and sustainable method to increase the quantity of biogas produced in a bio-digester hence a promising approach to enhance biogas production with implications for renewable energy and waste management practices. This report concludes with recommendations for further research and application of biogas on systems.
Investigating the Use of Waste Cooking Oil in Production of Biodiesel as a Supplement to Petroleum Fuels in Kampala District, Uganda
(2024-04-15) Fahad Paul Kirumira
This research explored the potential of waste cooking oil (WCO) for biodiesel production in Kampala, Uganda in search for a potential supplement to the petroleum fuels. The research aimed to attain this biodiesel as low cost fuel that will be blended with petroleum diesel in order to mitigate the high fuel prices. The research investigated factors influencing the viability of Waste cooking oil-based biodiesel production in Kampala, such as Waste cooking oil availability, collection methods. It also covered the biodiesel production process and the financial impact of the biodiesel compared to traditional diesel. Finally, the research was able to conclude Waste cooking oil-based biodiesel as viable supplement to petroleum diesel due to the compatibility in the engine performance and an overall price reduction in fuel price by 4% per litre.
Investigating the Use of Rice Husk Ash to Improve the Dewatering Performance in the Sludge Drying Beds
(2024-04-15) Chelsea Murungi
Lubigi faecal and waste water treatment plant in Namugoona, Uganda adopted the non-conventional technology for treatment which possess a unique characteristic for the treatment system. In spite of the system’s capacity to manage human excreta from both onsite and offsite sanitation systems, there is a high solid loading due to the incoming large volumes of wastes beyond the design capacity and an addition long drying period for the sludge thus limited sludge drying beds thus need for optimum utilization of the drying beds. The research project was investigating the use of rice husk ash to improve the dewatering performance of sludge in the sludge drying beds. Varying proportions of rice husk ash 0%, 4%, 7% and 10% of the sludge weight (30kgs) were mixed with sludge to monitor dewatering effectiveness after every seven days. The key parameters monitored were moisture content, total solids and volatile solids expressed in percentage (%) during both the dry and wet season in order to assess the effect of seasonal variation. During the wet and dry season, sludge with 0% (no Rice husk ash added) had the highest moisture content of 70.9% and 57.2% respectively, 4% dose had the lowest moisture content of 35.4% and 27.3% respectively and 10% dose had the lowest volatile solids of 21.4% and 22.3% respectively after 28days. The moisture content obtained for each season was within the recommended range of (30-40) % for sludge to be removed. Therefore, 4% dose of rice husk ash had the best dewatering performance in comparison to 0%, 7% and 10% and hence was the optimum dosage.
Treatment of Industrial Effluent Using Zeolites: A Case Study of Biyinzika Poultry Slaughterhouse
(2024-04-15) Bushendich Judah Kwemoi
In order to ensure environmental protection, wastewater requires treatment before it is discharged into the environment. This research looks to improve the quality of industrial effluent through treatment using natural zeolites. Samples were collected from Biyinzika poultry slaughterhouse and tests were carried out on them. Preliminary tests indicated high COD, BOD, Turbidity, TN and TP values in comparison to the national standards. The high BOD and COD values were attributed to the high organic loading of the effluent from the plant. This therefore meant that secondary treatment was required aside from the existing wastewater treatment system. The main objective of this research and the design were achieved. The design consists of a secondary treatment system comprising of zeolites located after the initial treatment processes. This will ensure that the effluent is treated to the required standards before discharge. The use of natural zeolites increased the efficiency of the treatment process. There was a high percentage reduction in all quality i.e. maximum turbidity, BOD, COD, TN and TP with percentage reductions of 75.7%, 81.3%, 90.8%, 64.2% and 89% respectively. All the quality were also treated to the required standards for discharge therefore implying the main objective the research was achieved.
Investigating the Use of Calcined Dolomite to Stabilize Expansive Soils
(2024-04-15) Ronald Byishimo
Soils which possess high amounts of clay content are more susceptible to shrink and swell behaviors due to varying moisture contents. This makes it hard for such soils to be suitable for engineering structures to be constructed on them for example roads, foundations and buildings. For a long time, soil stabilization has been used as a technique to modify such soils in order to change their properties so that they can favor construction of different structures. Cement and lime have been the most common stabilizers that aid chemical stabilization of soil. However, these two are so much competitive on market hence necessary to find other alternative materials that can perform the same purpose of stabilizing soil. This study explored using calcined dolomite to improve expansive soil. Various lab tests like sieve analysis, hydrometer tests, plasticity tests, compaction tests, strength tests, and swelling tests were performed. The untreated soil was a highly plastic clay of PI 38.9 and LL 61% and therefore unsuitable for subgrade road construction. The soil was mixed with different amounts of calcined dolomite (5%, 10%, 15%, and 20%). A 10% mix showed the best results, significantly reducing fine particles and plasticity that is from a PI of 38.9% to 12.2%. While density increased slightly, water content also decreased. Importantly, swelling and shrinkage of the soil were greatly reduced. Strength also increased considerably as CBR increased from 6.4% to 31.7%. These findings suggest calcined dolomite could be a promising and effective method for stabilizing expansive soils.
Investigating the Use of Lime Kiln Dust as a Filler in Asphalt Concrete for Durable Flexible Pavements
(2024-04-08) Steven Kisitu
Primarily utilized in Uganda, flexible pavements are made of bitumen, aggregates, and mineral filler. Investigating the use of lime kiln dust as a mineral filler in asphalt concrete for long-lasting flexible pavements in proportions by mass of the active filler of 4% was the primary goal of this study. The Marshall test, determining the engineering parameters of bitumen, aggregates, and mineral filler, as well as measuring the asphalt mixtures' indirect tensile strength (ITS), were the primary techniques employed. For each mix, a number of factors need to be ascertained, including Marshall stability, flow, unit weight, air voids (Va), voids filled with asphalt (VFA), and voids in the mineral aggregate (VMA). Air voids decreased from 5.7% to 4.9%, Marshall stability increased from 14.8 to 17.1%, and indirect tensile strength wet strength increased from 81% to 90% as a result of using lime kiln dust. Findings suggested that adding 4% of lime kiln dust filler increased the stability and stiffness of asphalt mixtures, enhancing their resistance to rutting; however, experiments utilising different percentages of lime kiln dust should be experimented. Accordingly, this study demonstrates that 4% lime kiln dust can be added to asphalt concrete as a mineral filler to decrease air voids, increase mix stability, and eventually strengthen the asphalt mixture's rigidity and durability.
Investigating the Use of Crushed Granite Stone and Incinerated Waste Ash in the Stabilization of Expansive Soils
(2024-03-16) Andrew Tusubira
Crushed granite stone is produced in large amounts during the cutting and processing of granite rocks at manufacturing factories. Thus, an attempt has been made here to define the role of crushed granite in enhancing the geotechnical behaviour of expansive soil in order to make it suitable for construction. In addition, this study aims to assess the use of granite stone and incinerated waste ash to stabilize expansive soils for subgrade. On natural and stabilized expansive soils using a constant portion of crushed granite as 30% with an increment of incinerated waste ash portion with a varying range from 2% to 8%, extensive geotechnical tests such as Atterberg limits, compaction characteristics, California bearing ratio (CBR), and swelling percentage have been carried out. The outcomes demonstrated that crushed granite stone is a useful tool for controlling swelling behaviour and enhancing soil plasticity. Furthermore, the findings demonstrated that CBR rises when incinerated waste ash content increases and that this increase peaks at 6% with a maintained 30% of crushed granite stone before declining. Therefore, this sum might be considered the ideal value of incinerated waste ash and crushed granite stone respectively.
Investigating the Use of Crushed Granite Stone and Ash From Waste Incineration to Stabilize Expansive Subgrade Soil
(2024-04-15) Peter Ashaba
Expansive soils pose significant challenges in civil engineering projects due to their high plasticity index (PI) and low California Bearing Ratio (CBR) values, often failing to meet standard requirements. This study investigates the effectiveness of locally available materials, crushed granite stone (CGS), and waste incineration ash (WIA), in stabilizing expansive soils in Kawanda Town Council, Wakiso District. Initial soil tests revealed unsatisfactory CBR and PI values. Subsequent addition of 30% CGS resulted in a notable increase in CBR values, meeting Ministry of Works and Transport (MoWT) standards. However, the PI value remained above the permissible limit at 26.2%. To further enhance soil stabilization, varying percentages of WIA (0%, 2%, 4%, 6%, and 8%) were introduced while maintaining the 30% CGS ratio. The results demonstrated a decrease in PI values with increasing WIA content, reaching a minimum of 22.3% at 8% WIA. Optimization analysis revealed that a combination of 30% CGS and 8% WIA yielded the most favourable outcomes, achieving optimal values for CBR, Maximum Dry Density (MDD) and Optimum Moisture Content (OMC), Plasticity Index (PI), and Liquid Limit (LL). This finding underscores the efficacy of using locally available materials for stabilizing expansive soils, offering a sustainable solution for civil engineering projects in the region.
Investigating the Use of Acrylic and Fiberglass Composite for Packaging of Biogas in Institutions of Learning in Mukono Municipality
(2024-04-15) Alden Job Openjtho
This report presents the development of an innovative bio-gas storage solution using a composite material blend of acrylic and fiberglass, designed to address the limitations of traditional storage methods in institutional settings. The project encompasses a comprehensive study that begins with the analysis of the chemical composition of bio-gas produced in institutions in Mukono Municipality, guiding the design criteria, for the storage cylinder. Utilizing Computer-aided design and finite element analysis, the cylinder meticulously designed to withstand internal pressures and operational demands, ensuring both safety and efficiency. The fabrication process highlighted the practical application of composite materials, demonstrating their suitability for bio-gas storage through a blend of durability, cost-effectiveness, and environmental consideration. A cost-benefit analysis underscored the economic viability of the composite cylinder, positioning it as a superior alternative to existing and steel options by balancing initial investment with operational longevity and maintenance requirements. The findings contribute valuable insights into the application of composite materials in renewable energy storage, proposing a scalable, sustainable solution for bio-gas management that aligns with global energy sustainability goals. The report culminates the recommendations for further research and development, suggesting pathways to optimize design and fabrication processes, enhance operational efficiencies, and expand the adoption of composite bio-gas cylinders in diverse contexts.
Assessing the Use of Activated Carbon to Increase Biogas Production
(2024-04-15) Sandra Namulumba
This research focuses on the need to increase the quantity of biogas produced in a bio-digester considering the required conditions like temperature ph, the feeding rate are all met according to the given standards. This study aims to assess the use of activated carbon to increase the quantity of biogas produced at the National Livestock Resources Research Institute biogas plant while using the same amount feedstock. The results from this study indicated an increase in methane production and decrease in carbon-dioxide in the bio-digester through the Direct Interspecies Electron Transfer Diet (DIET) process while using abiotic conductive materials like activated charcoal. The results of study contribute to the development of a cost-effective and sustainable method for increasing the quantity of biogas.
Investigating the Use of Rice Husk Ash to Improve the Dewatering Performance in the Sludge Drying Beds at Lubigi
(2024-04-15) Julius Kato
Sludge from onsite sanitation systems is called feces, and it is not dumped into a sewer. One of the management issues in Sub-Saharan Africa's heavily crowded urban slums is Faecal sludge. The high cost of emptying, the high density of dwelling units, and the long haulage routes to the treatment plants make it expensive to collect and transport Faecal sludge from slums to treatment facilities. The slum dwellers have adopted the use of additives that are marketed under the premise of being able to reduce volume of Faecal Sludge, odor emanating from it and the flies. As per the analysis, Faecal Sludge contains over 90 % water, dewatering it presents an important step for resource recovery (Shukla, A review on generation, characterization, containment, transport and treatment of fecal sludge and septage with resource recovery-oriented sanitation, 2023). This study aimed at investigating the use of rice husks ash to improve the dewatering performance in the sludge drying beds. The Lubigi Faecal sludge and Treatment Plant was considered as our area of study. The ability of the drying beds to dewater the faecal sludge was assessed by the determination of the Moisture Content and Total Solids of the faecal sludge and these were measured in terms of percentages.
Exploring the Use of Pineapple Peel Biosorbent in the Treatment of Namilyango Lagoon Effluent
(2024-04-15) Edwin Alyosha Ssekyondwa
This study addresses wastewater management by exploring the innovative use of pineapple peel biosorbents for the treatment of effluent from the Namilyango Lagoon in Mukono. The primary objective was to evaluate the efficacy of pineapple peel biosorbents in reducing Biochemical Oxygen Demand (BOD), Total Suspended Solids (TSS), and turbidity in the lagoon's effluent, thereby aligning with the discharge standards set by the National Environment Management Authority (NEMA). The methodology encompassed the preparation of the biosorbents through chemical activation using sodium hydroxide to enhance their adsorptive properties. Subsequent experimental treatments involved the application of these biosorbents to the lagoon effluent at various dosages, followed by rigorous physico-chemical analysis to quantify reductions in BOD, TSS, and turbidity. The study systematically determined the optimal dosage of biosorbents necessary to achieve compliance with environmental discharge standards. Findings from the research demonstrated significant reductions in all targeted effluent parameters, with the optimal biosorbent dosage identified at 250 mg/L. This dosage effectively reduced BOD, TSS, and turbidity levels to within NEMA's regulatory limits, showcasing the pineapple peel biosorbents' potential as a viable alternative to conventional wastewater treatment methods. The study further highlights the dual benefits of this approach: mitigating environmental pollution and repurposing agricultural waste, thus contributing to the circular economy. The implications of this research are far-reaching, offering a scalable, environmentally friendly solution to wastewater management challenges in Uganda and similar contexts worldwide. It bridges the gap between agricultural waste management and environmental engineering, providing a template for future innovations in sustainable wastewater treatment.
Investigating the Use of Linear Low-Density Polyethylene in Modifying Bitumen to Improve the Performance of Flexible Pavements Along Climbing Lanes
(2024-04-16) Derrick Adriko
This study examined the concept of bitumen modification to improve the performance of flexible pavements against rutting on climbing lanes. Such sections are subjected to slow moving heavy traffic and prolonged loading time hence categorized as severely loaded sections. As pavement temperatures rise, the asphalt binder softens and is unable to withstand the loads, leading to deformation. A case study along Bweyogerere – Jinja road climbing lane revealed premature deterioration in form of instability rutting in the asphalt layer. Using mechanistic and empirical approaches, aggregates and bitumen were evaluated to understand the failure. While aggregates showed good performance, the bitumen susceptible to temperature variations which reduced stiffness at high temperatures. Modifying bitumen with 2% LLDPE reduced the temperature susceptibility and increased the stiffness modulus which showed improved resistance to permanent deformation without compromising durability of the asphalt mixture as portrayed from Marshall test results. The modified specimens exhibited a 16.7% increase in tensile strength and a 42% increase in air voids at refusal density signifying increased flexibility under heavy loads and extending service life thereby addressing premature deformation issues at the road section.
Treatment of Industrial Effluent Using Zeolites a Case Study of Biyinzika Poultry Slaughterhouse
(2024-04-16) Daniell Wabbi
To ensure environmental protection, wastewater must be treated before being released into the environment. This study focuses on enhancing the quality of industrial effluent using natural zeolites. Samples were obtained from the Biyinzika poultry slaughterhouse and subjected to testing. Initial tests revealed significantly high levels of Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), turbidity, Total Nitrogen (TN), and Total Phosphorus (TP) compared to national standards, indicating the need for secondary treatment in addition to the existing wastewater treatment system due to the high organic content of the effluent. The primary goal and design of this research were achieved, which involved implementing a secondary treatment system with zeolites following the initial treatment processes to ensure the effluent meets required standards before discharge. The use of natural zeolites improved treatment efficiency, resulting in substantial reductions in turbidity, BOD, COD, TN, and TP by 75.7%, 81.3%, 90.8%, 64.2%, and 89%, respectively. These reductions ensured that all parameters met the required discharge standards, confirming the successful completion of the research objectives.
Investigating the Performance of Papyrus Ash in Concrete to Reduce Defects Caused Due to Carbonation
(2024-04-16) Philip Ajutu
Reinforced concrete structures are susceptible to a process called carbonation. This occurs when carbon dioxide from the atmosphere reacts with the calcium hydroxide in the concrete, gradually lowering its pH and compromising the protective oxide layer around the steel reinforcement. The papyrus ash used in this study was collected from buzilanjovu wetland in Mukoko. The Physical and mechanical properties of concrete ingredient such sand and coarse aggregates were determined and these included sieve analysis, ACV, AIV, moisture content, flakiness index, specific gravity and porosity. The control mix of a cement content of 400 kg, aggregate cement ratio of 4.15, 7% of the aggregate of the aggregate was used as fine aggregate, and a water cement ratio of 0.5 was used. The percentage replacement of fine aggregates with papyrus ash varied from 0, 2, 4, 6, 8, and 10 %. Concrete cubes of sizes 150 mm x 150 mm x 150 mm were casted and evaluated at 7 and 28 days. Increasing the replacement of fine aggregates with papyrus ash improved compressive strength but also increased porosity in hardened concrete. Despite this, compressive strength, porosity, and permeability remained within acceptable ranges (35.9 MPa, 17%, 0.34 cm/s respectively). The optimal replacement was 10%, meeting all criteria and design strength (35.9 MPa). Future research should aim to enhance workability, strength properties, and expand the material's applicability to higher concrete classes.
Investigating the Use of Wastewater Sludge-Based Fuels
(2024-04-16) Emmanuel Owino
This study examines the potential of wastewater sludge-based fuels through hydrothermal carbonisation, a process of converting biomass into carbonaceous material under elevated temperature and pressure in a closed system. The investigation aims to utilize wastewater sludge from the UCU Wastewater treatment plant as a biofuel, focusing on determining its properties as a suitable feedstock, optimizing process conditions for maximum hydrochar yield and briquette formation, evaluating the fuel characteristics of the resulting briquettes, and conducting a cost-benefit analysis. Proximate analysis, calorimetry, water boiling tests, and AHP analysis were employed. Optimal conditions were found at 230°C with 50% moisture content for 2 hours, yielding a heating value of 14.89 MJ/kg. Briquettes composed of 15% starch, 5% sand, and 80% hydrochar exhibited favourable properties, although reactor instability at high moisture content levels suggests the need for a stirred hydrothermal reactor. Further research to enhance briquette water resistance is recommended to improve durability for diverse applications.
Investigating the Use of Basalt Rock Powder in the Partial Replacement of Cement in Plain Concrete
(2024-04-16) Martin Kugonza
This research study aimed to determine the optimal replacement ratio of Basalt Rock Powder (BRP) that can be used as a supplementary material to partially replace cement in concrete, while achieving maximum compressive strength. Basalt rocks sourced from the Mugarama site in Kibaale District were crushed to form powder for use in the study. The physical and mechanical properties of concrete ingredients such as sand and coarse aggregates were evaluated through various tests, including sieve analysis, x-ray fluorescence, and water absorption. The control mix comprised 430kg of cement, 675kg of fine aggregate, 206kg of water, and 1007kg of coarse aggregate. Cement replacement with BRP ranged from 0% to 30%, with concrete cubes of size 150mmx150mmx150mm casted and tested at 7 and 28 days. The results indicated that an increase in the percentage replacement of cement with BRP led to an initial increase in compressive strength, peaking at 43.9MPa at 15% replacement, before gradually declining. Setting time decreased while workability increased with higher BRP replacement percentages. The compressive strength, setting time, and workability remained within acceptable ranges according to literature standards, with the 15% replacement ratio deemed optimal as it exceeded both the control concrete strength of 40.5MPa and the target strength of 35.1MPa.